Tuning control apparatus



Feb. 7, 1 950 ELLIOTT 2,496,455

TUNING CONTROL APPARATUS I Original Filed Dec. 16, 1943 4 Sheets-SheetJ.

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Feb. 7, 1950 H. F. ELLIOTT 2,496,455

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Feb. 7, 1950 H. F. ELLIOTT 2,496,455

I TUNING CONTROL APPARATUS Original Filed Dec. 16, 1943 4 Sheets-Sheet 4l0 (Afr/00f HIE/175525 INVENTOR.

[faroldj 5/140111 BY M, M, 73M )//7/ Patented Feb. 7, 1950 UNITED STATETUNING CONTROL APPARATUS Harold F. Elliott, Belmont, Mass.

Original application December 16, 1943, Serial No. Divided and thisapplication August 17, 1945, Serial N0. 611,051

21 Claims. (cl. 14-102) The present invention relates to improvements incontrol mechanisms and more particularly to improved control apparatusfor automatically and accurately tuning a radio receiving system to anydesired one of a plurality of signal channels. This application is adivision of copending application Serial No. 514,463, filed December 16,1943, and issued as Patent 2,411,619, on November 28, 1946.

It is an object of the present invention to provide automatic tuningapparatus for a radio receiver, which is extremely accurate and positivein its operation to move the frequency changing means to any settingcorresponding to a desired station, is compact in arrangement, and is ofsimple and inexpensive construction. v

It is another object of the invention to provide control apparatus ofthe character described, wherein a control unit pf improved ruggedconstruction is provided for moving the settable element of thefrequency changing means into each predetermined setting and for lockingthe element in the established setting, while at the same timepermitting the settable element to be moved in either direction awayfrom the established setting when actuated through a second, controlunit corresponding to a different predetermined setting.

According to a further object of the invention, each control unit isprovided with two positively acting lost-motion mechanisms of small sizeand an improved rugged structure for establishing the driving andlocking connections required to actuate the settable element to thedesired setting and then stop the same with precision accuracy, and alsofor permitting a wide range of adjustment of the settable element whenactuated through others of the control units.

It is another object of the invention to provide a lost-motion devicewherein an improved speed reducing mechanism employing a planetaryreduction gear assembly having an exceedingly high drive ratio, isemployed to actuate one of the relatively movable lost-motion parts ofthe device, thereby to enhance the accuracy with which another of theparts is actuated after the parts have been moved into predeterminedrelative positions.

In accordance with still another object of the invention, an improvedcam and cam follower assembly occupying a minimum of space is utilizedto provide the required lost motion in each device.

The invention, both as to its organization and method of operation,together with further objects and advantages thereof, will best beunderstood by reference to the following specification taken inconnection with the accompanying drawings, in which:

1 Fig. 1 is a fragmentary plan view illustrating improved controlapparatus characterized by the features of the present invention;

Fig. 2 is a fragmentary end view partially in section of the apparatusshown in Fig. 1;

Fig. 3 is an edge sectional view'illustrating the parts of one of thecontrol units provided in the control apparatus shown in Fig. 1;

Fig. 4 is a side view of the control unit shown in Fig. 3 with partsthereof broken away to show the driving relationship between certain ofthe elements of the mechanism;

Fig. 5 is an exploded perspective view of the parts making up one-halfof the control unit shown in Fig. 3;

Fig. 6 is a diagrammatic view illustrating the manner in which therotary control shaft of the control apparatus may be actuated through adriving connection provided by the parts of one of the control units;

Fig. '7 is a circuit diagram illustrating the manner of electricallyenergizing the electromagnets and driving motor of the apparatus shownin Fig. and

Fig. 8 is a sectional detailed view of certain of the parts included inthe apparatus shown in Fig. 1.

Referring now to the drawings, and more particularly to Figs. 1 and 2thereof, the improved control apparatus there illustrated is adapted tobe embodied in a radio receiving system for the purpose of selectivelyand automatically operating the frequency changing means ID of thesystem to different predetermined settings respectively corresponding todifferent desired signal channels. More specifically, the tuning orfrequency changing means Ill of the receiver is adapted to be actuatedto any one of a plurality of different settings, respectivelycorresponding to different stations, by a single driving motor I 3. Thismotor is arranged to rotate the settable shaft Illa of the tuning meansIn through any one of a plurality of driving connections which commonlyinclude the gears I l and I2, a rotary control shaft [5, an elongateddriving gear 22, and the two meshing motor driven gears 9 and 23. Thesedriving connections also individually include control units It which areaxially disposed along the rotary control shaft l5 and are arranged tobe selectively connected to the elongated driving gear 22 by means ofconnector units 51 individually associated therewith.

More specifically considered, all parts of the control apparatus aresupported between or upon two spaced-apart parallel extending framemembers l6 and I1. These members have suitable tie rods l8 and 66extending therebetween and anchored thereto at the end portions thereoffor the purpose of enhancing the rigidity of the structure.

The motor 13 is mounted upon the frame member I I at the inner sidethereof and is provided with a rotor shaft 9a which extends through anopening in the frame member I! and carries the driving gear 9. Asclearly shown in Fig. 8 of the drawings, the projecting end of the shaftI30. is of reduced section and is formed with a fiat lIb near the outerextremity thereof. The shoulder portion l3c of the shaft serves as astop or abutment for a washer 8 of a clutch assembly I through which theshaft Ba and gear are slip connected. More specifically, this assemblycomprises a stressed dish-shaped spring washer 5, the gear 9, a frictionwasher 4 and a collar 3. The parts of this assembly are maintained uponthe shaft end, with the washer 5 pressing the gear I against thefriction washer 4, by means of a set screw 2 which is threaded throughthe collar 3 to engage the fiat portion Nb of the shaft end.

The gear 23 which meshes with the driving gear 9 is preferably formed offiber or other like composition material, and is arranged to drive theelongated gear 22 through a spring connection which includes the coilspring 25. More specifically, the gear 23 is rotatably supported by aretaining bushing 24 which is rigidly mounted upon the shaft end of theelongated gear 22. A steel washer 25 butting against a shoulderedportion of the bushing 24 holds the gear 23 loosely upon the hub orbushing 24 so that it is free to rotate relative to the hub within thelimits imposed by the spring 26. One end of this spring is looped abouta friction screw 21 which holds the bushing 24 in a fixed position uponthe shaft end of the gear 22. The opposite end of the spring 26 ishooked into an aperture formed in the face of the gear 23. Thus, aflexible drive between the motor shaft l3a and the elongated gear 22 isprovided which serves to prevent any possible locking of the clutchunits to the driving gear 22 in the manner more fully ex- U plainedbelow.

As best shown in Fig. 1 of the drawings, the several control units I4are arranged between the two frame members [6 and I1 and each includesparts carried by three parallel extending shafts I5, 20 and 2|. The twoshafts 20 and 2! are fixedly supported by the members l6 and H at therespective ends thereof in the manner pointed out .below. The thirdshaft i5, as indicated above, constitutes the rotary control shaft andcarries stepped spacing sleeves 49 which are journaled in the framemember l6 and I! in an obvious manner. This shaft has the gear ll setscrew mounted thereon at the end thereof which is adjacent the settableelement lfla of the tuning means It. The several control units, whichare axially disposed along the three shafts i5, 20 and 2|, are ofidentical construction and arrangement. Accordingly, the arrangement ofthese units will be readily understood from a consideration of thecontrol unit I4a, the parts of which are detailed in Figs. 3, 4 and 5 ofthe drawings.

In brief, this control unit comprises an actuating element 30 which ismounted for rotation with the rotary control shaft 15 and to whichrotation may be imparted in different directions through two drivingconnections which respectively include the driving elements 4| a and4!!) and two combination speed reducing and lost-motion mechanisms. Eachcombination speed reducing and lost-motion mechanism comprises a pair ofmounted by means of an axis pin I'I upon the associated driving element4| 'for meshing engagement with the associated gears I2 and II; acamming element in the form of a ring 40 which is welded or pinned tothe associated gear II for rotation therewith about the shaft l5 and isprovided around its outer periphery with a cam lobe 42; a cam follower28 which is pivotally supported by means of a pin 43 at the outerperiphery and to one side of the actuating element It for engagement bythe associated cam lobe 42 when predetermined relative positions of thetwo associated gears I2 and 33 are established through operation of theassociated driving element 4!; and a stop or projection I4 which ispinned by means of pins I5 to the associated driving element 4i and isprovided with a projecting portion 44 adapted to be engaged by theassociated cam follower II when this cam follower is actuated by theasssociated cam lobe 42. Each gear II of the control unit is providedwith a different number of teeth than the associated gear 32 so thatduring operation of the associated driving element 4!, it is rotatedrelative to the associated driving element but at a much slower speed.For example, if the gear 23a is provided with sixtyone teeth and thegear 32a is provided with sixty teeth, a :1 drive ratio is providedbetween the driving element Ma and the gear 33a, such that the latterelement and the cam ring 40a connected thereto are rotated onerevolution for each sixty revolutions of the driving element 41a. Thus,the four elements 4| a, Ila, 32a and IIa combine to form an exceedinglycompact speed-reducing planetary gear assembly through which the camring 4041 may be rotated at slow speed in response to high speedrotation of the driving element 4 la. The other speed-reducing mechanismof the control unit, i. e. that comprising the four elements 4| b, 36b.32b and 33b, is an exact duplicate of that described and utilizes thesame drive ratio between the driving element Nb and the gear I3bthereof.

In the assembly of the control unit a, two shouldered bushings 28a and28b and two inner spacing rings 29a and 29b are utilized to provide therequired bearing surfaces for those elements 4i, II and 40 which arerotatable relative to the control shaft IS. The four identifiedsupporting members, together with the actuating element It and the twogears 32, are arranged in a stack, with the elements 4|, II and 40assembled thereon, in the manner just illustrated in Fig. 3 of thedrawings. Assembly pins II extending through the stack at severalpositions about the axis of the stack are utilized to provide clampingengagement between the parts 28, 2., III and I2, thereby to maintain theenumerated parts of the control unit in their assembled relationship. Inthis regard, it is pointed out that each bearing ring 29 has a thicknesswhich is slightly greater than the combined thicknesses of the twoelements II and 40 which it supports, whereby these two elements arepermitted to rotate freely about the bearing ring 29 without bindingengagement with the adjacent elements II and I2. springs I9 are utilizedto bias the lobes 46 of the cam followers Il into engagement with theperipheral surfaces of their respective associated camming elements 40.More specifically, and as best shown in Fig. 5 of the drawings,that.peripheral portion of the actuating element I! which is disposedadjacent the free end of the camming element Ila is cut away to providea space within which the coil spring Isa may be connected at oppositeends to the free end of the cam follower Ila and the actuating element88. This spring connection serves at all times to bias the lobe 48a ofthe cam follower 88a into engagement with the outer peripheral surfaceof the camming ring 48a. An identical arrangement is utilized to biasthe lobe 48b of the cam follower 3822 into engagement with the outerperipheral surfaces of the camming ring 4812, it being noted in thisregard that the two cam followers are disposed upon opposite sides ofthe actuating element 88.

From the above explanation it will be clearly apparent that each controlunit is exceedingly compact in arrangement and is entirelyselfcontained, such that it may be removed from the rotary control shaftl5 without disassembly of the parts thereof. As best shown in Figs. 1and 8 of the drawings, bushings 48 are utilized fixedly to support eachcontrol unit |4 upon the rotary control shaft l5 and to maintain therequired axial spacing between each adjacent pair of control units. Morespecifically, the inner peripheral portion of the supporting stack ofeach control unit is clamped between the oppositely arranged shouldersof two shouldered bushings 48, these bushings being provided with innerflatted surfaces which are adapted to engage the flat |5a of the shaftl5 to provide a fixed mechanical connection between the shaft and thecontrol unit which the bushings support. At the ends of the controlshaft |5, the stepped spacing sleeves 49 are provided, each of whichincludes a portion 49a of reduced diameter which is journaled within anopening provided in the adjacent one of the two frame members l8 and l1.

In order frictionally to clamp the control units 4 between theshouldered portions of the bushings 48 upon which they are respectivelysupported, a spring washer assembly comprising the two bushings 58 and5| and the spring washer 52, and a clamping assembly comprising thethree parts 53, 55 and 58 are provided. More specifically, thedish-shaped spring washer 52 is disposed between the two bushings 58 and5| to retain a slight clamping pressure against the assembly stack ofeach control unit regardless of the setting of the clamping assembly.This assembly comprises a camming member 53 having camming sides 54which engage a pin 55 extending through the shaft l5, and is providedwith a cross bar which is threaded to receive a screw 58. In itsengagement with the shaft l5, this screw may be utilized to move themember 53 radially of the shaft for the purpose of exerting an axialclamping pressure upon the parts 49, 48, 58, 5| and 49b, in the mannermore fully explained below.

The driving elements Ma and 4|b of each control unit H are in meshingengagement with pinions 58 and 59 respectively carried by the twostationary shafts 2| and 28. More specifically and as best shown in Fig.1 of the drawings, the pinions 58 and 59 through their meshingengagement witheach other, are so arranged that they rotate the drivingelements 4| a and 4|b in opposite directions. The pinions 58 are axiallyaligned and freely rotatable on the shaft 2|, each thereof being formedwith a toothed portion and a spacing portion 58a for positioning thenext adjacent pinion so that the toothed portion thereof is directlyopposite the driving element 4|a of the associated control unit. Thepinions 59 are of similar construction, each thereof being provided witha spacing portion 58a for properly positioning the toothed portion ofthe next adjacent pinion. Assembly of the pinions 58 and 58 upon therespective associated-shafts 2| and v 28 is maintained by bushings '85which are frictionally engageable with their respective associatedshafts by means of friction screws 88. The threaded ends of thetwo'shafts28 and 2| are held by nuts 88 to tie plates 81, and extendthrough the frame members l8 and I1, the nuts 88 serving to hold the tieplates against the pinion assembly and to space the pinions from theframe members l8 and I1. Nuts 89 located upon the outside of the framemembers" and 11 are utilized fixedly to mount the shafts 28 and 2|thereon.

For the purpose of selectively connecting the elongated gear 22 indriving relationship with any one of the control units l4, connectorunits 51 are provided individual to the control units. Each connectorunit comprises an idler pinion 88 pivotally supported by means of .apivot pin 8| upon an L-shaped rocker arm 82 which is loosely mountedupon the shaft 2|. 88 is in meshing engagement with its associatedpinion 58. At its projecting end, each rocker arm 82 carries an armaturepiece 63 which is adapted to be attracted into engagement with theproject-'- ing core end 88 of an electromagnet 81, thereby to move theidler pinion 88 into meshing engagement with the elongated drive gear 22in response to energization of this magnet. In order normally to biasthe rocker arm 82 'of each connector assembly 51 to a position whereinthe idler pinion 88 is disengaged from the gear 22,

each rocker arm is spring connected through a coil spring 85 to the tierod 88. Movement of the rocker arms 82 under the influence of theirrespective associated retracting springs 85 is limited by the tie rod l8which is positioned in the paths of movement of the rocker arms and isprovided with a cushioning sleeve i9 formed of rubber or other softflexible material. The electromagnets 81 are all bolted to a crossbar 89which extends transversely between the two frame members i8 and I1, andis anchored to these' members at the ends thereof. This crossbar alsosupports a terminal strip 18 formed of Bakelite or other suitableinsulating material having ter-- m nal elements suitably mounted thereonfor connection with the winding terminals of the electromagnets 81.

The motor I3 is of the unidirectional type and may be so arranged thatits motor is rotated in a counter-clockwise direction as viewed in Fig.6 of the drawings. With the driving gear 22 thus rotating in a clockwisedirection, the idler pinions are adapted for counter-clockwise rotationwhen engaged with the driving pinion 22. Accordingly, when any selectedidler pinion 88 is actuated into meshing engagement with the drivinggear 22, the meshing engagement of the gear 88 with its associatedpinion 58 produces a force which acts to pull the pinion 88 into meshingengagement with, the driving gear 22, thereby to lock the pinion anddriving gear in mesh during the tuning operation. Since this meshingengagement holds the armature piece 83 in its attracted position againstthe magnet core 68, a mechanical pressure urgingthe armature piece 83toward the magnet core occurs concurrently with the electricalattraction of this piece by the core, whereby the magnet is aided inoperating the movable parts of the connector assembly. The magnets 81,therefore, need only be large enough to attract their associatedarmature pieces into engagement with the magnet cores. This utilizationof the mechanical reaction be- Each idler pinion acac a tween any one ofthe pinions II and its engaged pinion it provides for the use ofrelatively small magnets 61, since each magnet merely functions toinitially engage the idler pinion with the driving gear; the pulling ofthe pinion into meshing engagement with the gear being sufficient tomaintain the geared or interlocked engagement between the two elementsso long as the driving gear is rotating. The coil spring 26 throughwhich the gear 22 is driven by the motor I3 insures positivedisengagement of the idler pinion l embodied in any actuated connectorunit when the electromagnet i1 of the unit is deenergized uponcompletion of a tuning operation.

For the purpose of energizing the motor I3 and selectively controllingthe energization of the connector magnets 61 individual to the severalcontrol units Il, the control circuit illustrated in Fig. 7 of thedrawings may be employed. Briefly considered, this circuit comprises atransformer 15 having a primary winding 15a adapted to be connected to,a suitable commercial frequency source of alternating current and asecondary winding 15b from which current is delivered for energizing themotor I3 and selectively energizing the magnets 61. The transformer I5also includes a low voltage winding 150 for supplying cathode heatingcurrent to the heaters of the tubes provided in the radio receiverequipped with the illustrated control apparatus. To additional secondarywindings d and 15s are provided, which are included in the illustratedfull wave rectifying circuit, this circuit being utilized to supply thescreen and anode potentials required for operation of the various tubesprovided in the receiver. In order selectively to control theenergization of the motor H, the magnets 61, the cathode heatingcircuit, and the rectifying circuit, switching equipment is providedwhich includes an off switch 83, push button switches ll individual tothe various magnets 51, and a relay switching unit indicated generallyat 85. This unit includes two mechanically interlocked magnets 16 and18, The second of which includes an armature I9 interlocked with thearmature ll of the magnet I6 and arranged to control three sets ofcontacts ll, II and 82. The magnet I6, together with the armature andcontact spring assemblies thereof, is shown in Fig. 1 of the drawings asbeing mounted upon an assembly plate 96 which is rigidly secured to theframe member I1. 7

In considering the operation of the control apparatus as describedabove, it may be assumed that this apparatus is to be utilized toactuate the tuning means III of the receiver to the particular settingcorresponding to the control unit Ila thereby to tune the receiver forthe reception of signals radiated at the particular carrier frequency towhich the control unit Ila corresponds. In order to initiate theoperation of this control unit, the push botton switch Ola associatedwith this control unit is actuated to its closed circuit position,thereby to complete a circuit for energizing the connector magnet 61individual to the control unit Ila in series with the driving motor I!and the winding of the magnet 16. When energizing in this circuit, themagnet 16 attracts its associated latching armature 11, thereby torelease the spring biased armature I9 of the magnet 18. The armature ISin moving to its retracted position, closes the contacts 60 to completethe cathode heater circuit, and at the contacts II and 82, completes thehigh voltage rectilying circuit in an obvious manner.

When the electromagnet ll individual to the control unit Ila is thusenergized, the armature piece 83 of the connector unit 51 associatedwith this control unit is attracted, whereby the rocker arm 62 of theconnector unit is pivoted about the shaft 2I against the bias of itsretracting spring to move the idler pinion it into engagement with thedriving gear 22. Thus, a driving connection is established between themotor II and the driving elements lla and llb of the con trol unit Ila.As will be seen from Fig. 6 of the drawings, when the motor I! isenergized in the manner just explained, it rotates the gear 9 in acounterclockwise direction through the slip clutch connection providedbetween this gear and the motor shaft I3a. Accordingly, the gear 23 isactuated to rotate the elongated drive gear 22 in a clockwise directionthrough the resilient connection provided by the spring 28. As a result,the two pinions 5B and 59 are respectively rotated in clockwise andcounterclockwise directions through the driving connection afforded bythe idler pinion 60 in its engagement with the driving gear 22. Thus,driving connections are provided, whereby the driving element lla isrotated in a counterclockwise direction and the driving element llb in aclockwise direction rela tive to the rotary control shaft l5.

During rotation of the driving element lla, the planetary gear 36a isrotated about the two gears 32a and 33a and, due to the toothdifferential between these two gears, the gear 32a and the cammingelement lfla connected thereto are rotated in the same direction as thedriving element lla, i. e. in a counterclockwise direction about therotary control shaft I5. The driving element llb similarly functions todrive the camming elements llb in a clockwise direction relative to therotary control shaft [5 through the driving connection provided by thespeedreducing differential gears 32b, 33b and 38b. During such rotationof the two camming elements 40a and lIlb the actuating element II forthe rotary control shaft I5 remains stationary until the cam lobe l2carried by one of the two camming elements is positioned to actuate itsassociated cam follower 38 into engagement with the associated stop 34carried by the associated driving element lI. With the camming elementlob rotating in the direction indicated, i. e. in a clockwise direction,the cam lobe l2b thereof will engage one of the camming surfaces of thelobe lib when it is moved to the proper position relative to theactuating element 3.. After such engagement, and during continuedrotation of the camming element llb, the two engaged lobes l2b and libcoact to pivot the cam follower 38b in a counterclockwise directionabout I its pivot pin l3b so that the stop engaging head lib thereof ismoved radially outward from the shaft I5. Approximately when the lowerknife edge of the lobe llb is moved to bear against the upper knife edgeof the lobe l2b, the locking head lSb of the cam follower llb-ispositioned to be engaged by the projection llb of the stop element llb.The engaged surfaces of the two engaged elements llb and llb are cut ona bias so that the continued movement of the driving element lib,following engagement of the two elements, provides a solid mechanicalinterlock therebetween.

In a manner entirely similar to that just described, the camming elementllla is rotated until the cam lobe l2a thereof is moved into engagementwith the lobe Ila of the cam follower In. Here again, when the two lobes42a and 48a are relatively so positioned that their knife edges are bythe stop 34a, a direct mechanical connection is l provided between thedriving element 4 Ia and the actuating element 30. When this connectionis established, rotation of the planetary gear 36a about the two gears32a and 33a is obviously ar- 1 rested with the result that relativemovement between the parts 30, 40a, 33a, 32a, a and la is entirelydiscontinued. In a similar manner, relative movement between the parts4Ib, 36b,

32b, 33b, b and 30 is arrested when the cam follower 38b is moved to aposition for engagement .by the stop b carried by the driving elementlIb.

From the above explanation it will be apparent that depending upon theinitial setting of the I control unit Ila, the rotary control shaft I5and the actuating element 30 will be rotated in one direction or theother by one of the two driving of the actuated connector unit 51 isdisengaged from the driving gear 22. In this regard it is noted thatupon deenergization of the driving motor I3, the coil spring 26connected between the gear 23 and th driving gear 22 provides akick-back action to insure release of the idler pinion by the drivinggear 22.

The manner in which the remaining control units I4 may, throughselective energization of the magnets 61 by the push button switches 84,be actuated for the purpose of driving the settable element Illa to itsother predetermined settings, will be clearly apparent from the aboveexplanation with reference to the operation of the control unit I la. Ifat any time it is desired to turn oil the receiver after a period ofoperation, the off switch 83 may be momentarily operated to its closedcircuit position, thereby to complete an obvious circuit for energizingthe winding of the magnet 18. This magnet, in attracting its associatedarmature I9, opens the contacts 80 to deenergize the cathode heaters ofthe tubes provided in the receiver. tacts 8i and 82, the magnet 18 opensthe B sup- 1 ply circuits to the tubes and deenergizes the elements lIaor 4Ib. Thus, if the stop at engages the cam follower 38a before thestop 34b engages the cam follower 38b, the actuating element 30 andcontrol shaft I5 will be rotated in a counterclockwise direction to thepredetermined setting to which the control unit Ila corresponds.

Conversely, if the stop 34b is moved to engage the cam follower 381)before the stop 34a engages the cam follower 38a, the actuating drivingelement 4| with which they are mechanicathode heaters of the full waverectifying tube provided in the rectifying circuit. As the armature I9is moved to its attracted position, the free end thereof rides over thelocking portion of the armature 11. After the switch 83 is released todeenergize the winding of the magnet 18, therefore, the armature I9 isheld in its attracted position by the latching farmature II of themagnet I8.

During the above described movement of the shaft I5 to the particularsetting corresponding to the control unit Illa, the movable parts of thenonactive control units are also moved to In either case, the actuatingelement 3| and the shaft I5 are rotated at the speed of the callyconnected until the nonengaged stop and cam follower are brought intoengagement. When both of the two stop elements 34a and b are moved intoengagement with the cam followers 38a and 38b, respectively, a lockingconnection is obviously established which prevents continued rotation ofthe parts I5, 30, ll, 58, 59, 60, 22, 23 and 9. Thus, the entire geartrain extending back to the motor driving gear 9 is locked up when theshaft I5 is rotated to the predetermined setting corresponding to theactuated control unit Ila. After this train has been locked up,continued rotation of the motor shaft In is permitted through the slipclutch connection between this shaft and the gear 9;

When the new setting of the settable element Illa for the tuning meansI0 is established in the manner just explained, the operator will beapprised of this fact through reception of the desired station and mayrelease the push button switch a to deenergize the driving motor I3, theenergized electromagnet i1 and the winding of the magnet IS in anobvious manner. When the magnet 16 is thus deenergized, its springbiased armature I1 is retracted to a position beneath the armature 19 ofthe magnet I8, but this operation is obviously without eflect, and thepower circuits of the receiver remain enersized. When the electromasnet81 of the clutch produce unlatching relative movement between the camand cam follower parts of one of the lost-motion mechanisms provided ineach unit. In this regard it will be understood that as the controlshaft I5 is rotated, all of the actuating lements 30 individual to thevarious control units are rotated therewith. The action which occurs inthe nonactive units will be more fully apparent from the followingexplanation relating to the movement of the parts provided in thecontrol unit Ma when the control shaft I5 is driven to anotherpredeterminted setting by another of the control units. Thus it may beassumed that after the rotary control shaft I5 is operated to thesetting corresponding to the control unit Ha; such that the camfollowers 38a and 38b are respectively in engagement with the stops 34aand 34b, the shaft I5 is rotated by a second control unit in a clockwisedirection. During such rotation of th shaft I5 the cam follower 38aremains in engagement with the stop 34a to prevent relative movementbetween the parts 4Ia, 36a, 32a, 33a, 40a and 30 of the control unit.Thus, the driving gear Ma which is rotating in a clockwise direction, isrendered operative to drive the driving element 4Ib in a clockwisedirection through the driving connection afforded by the meshing pinions58 and 59. The relative movement thus produced between the drivingelement IIb and the actuating element 30 by rotating these two elements.in op o- At the conassasss 11 will be clearly apparent from thefollowing explanation.

Assuming now that the rotary control shaft it is rotated in acounterclockwise direction away from the predetermined settingcorresponding to the control unit l4a, the actuating element 30 anddriving element 4'|b of this unit are rotated in the same direction dueto the engagement between the cam follower 34b and stop 34b respectivelycarried thereby. The gear 32a is also rotated in a counterclockwisedirection with the two elements 30 and lib. Also, and due to the drivingconnection aflorded by the pinions BI and 58, the driving element 4la isrotated in a clockwise direction relative to the shaft l5. With the twoelements 4 la and 32a thus rotating in opposite directions and with theelement 4la rotating in a direction opposite the direction of rotationof the actuating element II, the planetary gear its functions to rotatethe gear 33a and naming element 404 in a clockwise direction relative tothe actuating element 30. Thus, the cam lobe 42a is withdrawn frombeneath the lobe 46a of the cam follower Ila to prevent reengagement ofthe stop 34a with the cam follower 34a after the two elements 4 la and3| have been relatively rotated through one revolution. As relativemovement between the two elements 4 la and It continues, the cam lobe42a is gradually backed away from the lobe 484 until, these two lobesare separated by a distance which is determined by i interferencewhatever from the nonactive control units. This is due to the fact thatduring operation of any one of the control units to establish thedesired setting for the shaft II, the parts of the nonactive units areso moved rela- -tive to each other as to prevent a locking conof thepredetermined settingsrespectively corresponding to the several controlunits.

In order individually to adjust the various control units relative tothe rotary control shaft ll, thereby to provide for operation of thisshaft by the various control units to the desired predeterminedsettings, the screw 56 in the clamping mechanism is withdrawn until thecontrol units are freed for rotation relative to their respectiveassociated supporting bushings 48. The shaft I is then adjusted to adesired control position or setting by a suitable manual control knob(not shown) provided for manually actuating the settable element Illa ofthe frequency changing means ll. During such rotation of the shaft I!the spring washer 52 serves to maintain suflicient clamping pressureagainst the elements 28 of the respective control units to prevent theshaft from being moved relative to the control units, the movement ofthe rotary control shaft being taken up within each control unit in amanner which will be clearly apparent from the above explanation. Whilethe shaft II is held in the position to which it is adjusted, bymanually gripping the control knob of the manual actuating means, theswitch .4

associated with the particular control unit which is to be utilised inoperating the rotary control shaft to the manually established set- 5ting, is operated to energize the driving motor I! and to engage theidler pinion ll of the connector unit individual to the control unitwith the driving gear 22. The motor II is thus rendered operative todrive the movable parts of the selected control unit until these partsare lockingly engaged in the manner explained above. During the finalportion of the operation of the selected control unit and moreparticularly after one of the cam followers 34 is engaged by itsassociated stop I4, all parts of the control unit are rotated relativeto the shaft II and the bushings 48 upon which the contrcl'unit issupported. Thus, the selected control unit is actuated to a positionrelative to the rotary control shaft ll, such that when the shaft andcontrol unit are subsequently locked together, the control unit canthereafter only operate the rotary control shaft to the particularsetting which it occupies when the locking operation is completed. Theabove described procedure may be repeated for each of the other controlunits l4, in order to establish the other predetermined settings desiredfor the rm tary control shaft ll. During each setting operation, thecontrol units which are not being adjusted are maintained in adiustmentbecause of the fact that their frictional engagement with the bushings4| is suflicient to maintain their established positions relative to theshaft ll. When all of the control units l4 have been adjusted, the screwIt may be tightened to frictionally lock all of the control units l4 infixed positions relative to the shaft II, in a manner which will beclearly apparent from the foregoing explanation.

While one embodiment of the invention has been disclosed, it will beunderstood that various modifications may be made therein, which arewithin the true spirit and scope of the invention.

I claim:

1. In a radio receiver, a tuning system comprising: means for operatingthe tuning element of the receiver to a predetermined setting from aparticular direction, and means including a speed-reducing planetarygear assembly responsive to the operation of said element to saidpredetermined setting from said direction for arresting the same.

2. In control apparatus for operating a settable element to apredetermined setting, a speed-re- 55 ducing planetary gear asembly,means including said assembly for operating said element to saidpredetermined setting, and means coacting with said assembly andresponsive to operation of said element to said predetermined settingfor locking the same against further operation.

3. In control apparatus which includes means for driving a rotatablecontrol shaft to different predetermined settings through different 65connections, means including a speed-reducing planetary gear assemblyfor locking said shaft against rotation when it is rotated to one ofsaid predetermined settings through one of said driving connections, andmeans including said as- 7 sembly for permitting said shaft to berotated away from said one predetermined setting when driven through asecond of said driving connections.

4. In control apparatus which includes means 75 for operating a rotarycontrol shaft to a prede- 13 termined setting, a pair of relativelyrotatable gears having different numbers of teeth, a rotatable drivingelement, a planetary gear rotatably supported upon said driving elementand meshing with said pair of gears, whereby relative movement betweensaid pair of gears is produced in response to rotation of said planetarygear thereabout by said driving element, and means controlled by therelative movement between said pair of gears for locking said rotarycontrol shaft against continued rotation when it is rotated to saidpredetermined setting.

5. In control apparatus which includes means for operating a rotarycontrol shaft to a predetermined setting, a pair of relatively rotatablegears having different numbers of teeth, a rotatable driving element, aplanetary gear rotatably supported upon said driving element and meshingwith said pair of gears, whereby relative movement between said pair ofgears is produced in response to rotation of said planetary gearthereabout by said driving element, a cam actuated in response torelative movement between saidpair of gears, a cam follower actuated bysaid cam after said pair of gears are moved into predetermined relativepositions, and means including a stop adapted to be engaged by said camfollower for locking said rotary control shaft against continuedrotation when it is rotated to said predetermined setting.

6. In control apparatus which includes driving means for operating arotary control shaft to a predetermined setting, a control unitcomprising a pair of relatively rotatable gears having different numbersof teeth, a rotatable driving element provided with a stop and actuatedby said driving means, a planetary gear rotatably supported upon saiddriving element for meshing engagement with said pair of gears, wherebyrelative rotation between said pair of gears is produced in response tooperation of said driving element to rotate said planetary gear aboutsaid pair of gears, a cam actuated in response to relative movementbetween said pair of gears, an element mounted for rotation with saidrotary control shaft, and a cam follower pivotally supported upon saidlast-named element and actuated into engagement with said stop to arrestthe rotation of said rotary control shaft in response to the actuationof said cam to a predetermined position relative to said'-cam follower.

7; In control apparatus which includes driving means for operating arotary control shaft, a control unit comprising a pair of relativelyrotatable gears having different numbers of teeth, one of said gearsbeing mounted for rotation with said rotary control shaft and the othergear being rotatable about said shaft, a rotatable driving elementfreely rotatable about said shaft and actuated by said driving means, aplanetary gear rotatably supported upon said driving element for meshingengagement with said pair of gears, whereby said other gear is rotatedrelative to said shaft in response to operation of said driving,

element to rotate said planetary gear about said pair of gears, acamming element rotatable with said other gear about said shaft, asecond element mounted for rotation with said shaft, a cam followerpivotally supported upon said second element and actuated by saidcamming element in response to rotation of said camming element relativeto said shaft, and a stop carried by said driving element and engaged bysaid cam follower to arrest the rotation of said shaft in response tothe rotation of said camming elel4 nlilent to a predetermined positionrelative to said s aft.

8. In control apparatus which includes a settable element operative to apredetermined setting, a mechanism comprising a speed-reducing planetarygear assembly, means including said mechanism for operating said elementto said predetermined setting, and stop means coacting with saidassembly and responsive to operation of said element to saidpredetermined setting for locking the same against further operation.

9. In control apparatus which includes a settable element operative to apredetermined setting, a drive mechanism comprising a speed-reducingplanetary gear assembly and a pair of lost-motion parts which areactuated in response to operation of the parts of said assembly, meansfor establishing a driving connection for said element which includessaid gear assembly when said parts are moved into predetermined relativepositions, and stop means coacting with said mechanism and responsive tooperation of said element to said predetermined setting for locking thesame against further operation.

10. In control apparatus which includes driving means and a rotarycontrol shaft, a pair of relatively rotatable gears having differentnumbers of teeth, a rotatable driving element actuated by said drivingmeans, a planetary gear rotatably supported upon said driving elementand meshing with said pair of gears, whereby relative rotation betweensaid pair of gears is produced in response to operation of said drivingelement to rotate said planetary gear about said pair of gears, andlost-motion means controlled by the relative movement between said pair'of gears and operative to establish a driving connection between saiddriving means and said I shaft when said pair of gears are moved intopredetermined relative positions.

11. In control apparatus which includes driving means and, a rotarycontrol shaft, a pair of relatively rotatable gears having differentnumbers of teeth, a rotatable driving element actuated by said drivingmeans, a planetary gear rotatably supported upon said driving elementand meshing with said pair of gears, whereby relative rotation betweensaid pair of gears is produced in response to operation of said drivingelement to rotate said planetary gear about said pair of gears, acamming element rotatable about said shaft in response to relativemovement between said pair of gears, an actuating element mounted forrotation with said shaft, a cam follower supported upon said actuatingelement for movement radially of said shaft when engaged by the cammingportion of said camming element, and stop means carried by. said drivingelement I for engagement by said cam follower to establish a directdrive connection between said driving element and said shaft.

12. In a control unit for operating a settable element to apredetermined setting, driving means, a pair of speed-reducing planetarygear assemblies connected to be rotated in opposite directions by saiddriving means, means including one of said assemblies for operating saidsettable element to said predetermined setting, and means including theother of said assemblies for arresting the operation of said elementwhen it is operated to said predetermined setting.

13. In a control unit for operating a settable element to apredetermined setting, a pair of speed-reducing planetary gearassemblies, means 7 including one of said assemblies for operating saidaettable element to said predetermined setting from one direction, meansincluding the other of a said assemblies for operating said settabieele-- ment to said predetermined setting from the other direction, andmeans including both of said assemblies for arresting the operation ofsaid element when it is operated to said predetermined setting fromeither direction.

14. In control apparatus which includes means for driving a rotatablecontrol shaft in either of two directions to different predeterminedsettings through diiferent driving connections, means including a pairof speed-reducing planetary gear assemblies for locking said shaftagainst rotation when it is rotated to one of said predetermine-zlsettings through one of said driving connections, andmeans includingsaid assemblies for permitting said shaft to be rotated in eitherdirection away from said one predetermined setting when driven through asecond of said driving connections.

15. In control apparatus which includes means for driving a rotatableshaft in either of two directions to different predetermined settings; apair of speed-reducing planetary gear assemblies each actuated by saiddriving means, means including one of said assemblies for rotating saidshaft to one of said predetermined settings from one direction and forlocking said shaft against continued movement when moved to said onepredetermined setting by the other assembly, means including'said otherassembly for moving said shaft to said one predetermined setting fromthe other direction and for locking said shaft against continuedmovement when moved to said one predetermined setting by said oneassembly, an independent mechanism for completing a mechanicalengagement between said driving means and said shaft, and lost-motionmeans included in the driving connections between said assemblies andsaid shaft for permitting said shaft to be rotated in either directionaway from said predetermined setting when actuated through saidindependent mechanism.

16. In combination, a rotatable shaft, a driving element freel rotatableabout said shaft, 8. ring rotatable about said shaft and provided with acam lobe, speed-reducing means driven by said driving element forrotating said ring about said shaft, a member supported by said shaft,-a cam follower carried by said member and adapted for actuation by saidcam lobe, and means'coacting with said cam follower to establish adirect mechanical connection between said drivingelement and said memberwhen said cam follower is actuated by said cam lobe. 17. In combination,a rotatable shaft, a driving element freely rotatable about said shaft,a ring rotatable about said shaft and provided with a cam lobe, meansincluding a speed-reducing planetary gear assembly rotatably supportedby said shaft and actuated by said driving element for rotating saidring about said shaft at a fraction of the speed of rotation of saiddriving element, a member supported by said shaft, a cam followermovably supported upon said member for actuation by said cam lobe, andmeans coacting with said cam follower to establish a direct mechanicalconnection between said driving element and said member when said camfollower is actuated by said cam lobe.

18. A control apparatus for a controlled element comprising: a fastrotatable member operable over a multi-revolution range; a slowrotatable member operable over a range not exceeding one revolution;driving means for simultaneously rotating said members at a preselectedspeed ratio; a normally disengaged driving connection between saiddriving means and the controlled element and including said members; afollower mechanism for engaging one of said members to engage saiddriving connection between said driving means and the controlledelement; and means controlled by the other of said members forconditioning said follower mechanism to engage said one member.

19. A control apparatus for a controlled element comprising: a fastrotatable member operable over a multi-revolution range; a slowrotatable member operable over a range not exceeding one revolution;driving means for simultaneously rotating said members at a preselectedspeed ratio; a normally disengaged driving connection between saiddriving means and the controlled element and including said members afollower mechanism for engaging said fast member to engage said drivingconnection between said driving means and the controlled element; andmeans controlled by said slow member for conditioning said followermechanism to engage said fast member.

20. A control apparatus for a controlled element comprising: a fastrotatable member operable over a multi-revolution range; a slowrotatable member operable over a range not exceeding one revolution;driving means for simultaneously rotating said members at a preselectedspeed ratio; a normally disengaged driving connection between saiddriving means and the controlled element and including said members; afollower mechanism for engaging one of said members to engage saiddriving connection between said driving means and the controlledelement; and means responsive to a predetermined angular setting of theother of said members for conditioning said follower mechanism to engagesaid one member.

21. A control apparatus for operating a settable element to apredetermined setting comprising: a driving mechanism for said elementincluding a speed-reducing planetary gear assembly normally operativelydisconnected from said element; means for establishing a drivingconnection between said mechanism and said element through saidplanetary gear assembly when the parts of said mechanism are operated.to predetermined relative positions; and stop means coasting with saidmechanism and responsive to operation of said element to saidpredetermined setting for arresting all of the elements of theapparatus.

HAROLD F. ELLIO'I'I.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,095,373 Borland May 5, 19141,203,840 Bailey Nov. 7, 1916 1,437,373 White Nov. 28, 1922 1,777,490Hardie Oct. 7, 1930 2,285,414 Collins June 9, 1942 2,293,299 Mastney etal. Apr. 26, 1941 2,293,355 Olson et al July 12, 1941 2,391 470 May Dec.25, 1945

